Workshop Project:

Use paper to make a crane

Materials:

cardboard

Used paper sheets

sticky tape

Silicon glue

Piece of string

Geared electric motor

Electric wires

Batteries / a power source.

Tools:

scissors

glue gun

Make the column.

1. Cut three squares of cardboard (10 cm x

10 cm for example).

Two of them are for the base and top of

the column. If you want, the square for

the base can be a bit bigger than the

square for the top.

The other square is for the beam.

2. With paper sheets and sticky tape make four paper rolls.

3. Glue the four paper rolls to the two

cardboard squares for the column

as in the picture.

It is best to use silicone glue for to

unite the bars to the cardboard.

Use a very small amount of glue, it

will be easier to make the union and

if there is a problem and we have to

undo the union it will be a lot

easier.

4. Now we need to make smaller paper rolls that we will use

to “triangulate the structure”.

Think how many short paper rolls you need and of what

length and cut them.

In this example (see the picture) there are 16 rolls, 4 per

side.

5. Now glue the short rolls.

It is important that the unions of short rolls

always coincide in the same point.

6. Make three long paper rolls and enough short

paper rolls to make the beam.

7. On the cardboard square make a hole in the

centre (for the rotating axis that we will make

later)

8. Make the pulley with three circles of cardboard (two of the same size and one a little

smaller). Glue them together putting the small one in the middle.

if you have plywood you can make the outside (bigger) circles with plywood, this gives

a more solid pulley.

9. Glue the rolls together and then glue the cardboard square with the hole as in the

picture.

It is important that the pulley is in position when you glue the roll that is inside it!

Don’t glue the pulley to the roll! It must move!

10. Make the paper roll that will be the axis of rotation.

It’s length must equal the height of the tower.

11. Make a small roll that is wider than the

roll for the axis of rotation and glue it

vertically in the centre of the base.

The axis will be inside this small paper

roll.

12. Make a hole in the middle of the cardboard

square of the top of the column.

13. Make a hole in the middle of the cardboard

square of the beam.

14. Put the axis roll through the holes and into the paper roll at the base.

15. Now we have the structure of the

crane, the pulley should be in

place.

You can see in the picture that we

forgot to put the pulley! So now

we have to undo the union of the

roll at the end of the beam to put

the pulley and then unite the roll

to the rest of the structure again!

16. Next we cut a small piece of cardboard that will be the base for the motor

We glue the cardboard to the top of the beam, ideally in a place opposite the end of

the pulley. The reason for this is that if the motor is opposite the pulley it will also be

opposite the load and so the weight of the motor and gears will help to balance the

weight of the load.

17. Glue the motor on the piece of cardboard that is its support.

18. Glue one end of the string to the rod of the motor-gears mechanism.

19. Pass the string around the lever.

20. Connect two wires to the motor (one for

each connection).

For convenience, we will connect the

opposite ends of the wires to a connector.

And the wires from the power source to

this connector. We can glue the connector

somewhere on the beam. This helps to

prevent damage to the motor connections

and makes a more solid electric wiring.

21. Connect the power source wires to the

connector.

Our power source has an option to change

polarity, this is very helpful in this case because

by changing the polarity we change the direction

of rotation of the motor, so we control if the

load is going up or down.

If you don’t have this option then you will need a

way to do this.

22. You can attach the load to the string anyway you

like.

One option, for example, is to construct a

cardboard box and tie it to the string.

The crane is now finished. Test it!

Answer the following questions:

1) Is it better to put the motor on the beam near the load or far from the load? Why?

2) What is the maximum load that your crane can lift?

3) What happens if the load is bigger?

4) What can you do to increase the maximum load?